Re: Network performance degradation from 2.6.11.12 to 2.6.16.20

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Harry Edmon <[email protected]> wrote:

I have a system with a strange network performance degradation from 2.6.11.12 to most recent kernels including 2.6.16.20 and 2.6.17-rc6. The system is has Dual single core Xeons with hyperthreading on.
<cut>

Hi Harry

Can you check which "high-res timesource" you are using?

In the kernel log look for:
 kernel: Using tsc for high-res timesource
 kernel: Using pmtmr for high-res timesource

I have experinced some network performance degradation when using the "pmtmr" timesource, on a Opteron AMD system. It seems that the default timesource change between 2.6.15 to 2.6.16.
If you use "pmtmr" try to reboot with kernel option "clock=tsc".

On my Opteron AMD system i normally can route 400 kpps, but with timesource "pmtmr" i could only route around 83 kpps. (I found the timer to be the issue by using oprofile).

Cheers,
  Jesper Brouer

--
-------------------------------------------------------------------
MSc. Master of Computer Science
Dept. of Computer Science, University of Copenhagen
Author of http://www.adsl-optimizer.dk
-------------------------------------------------------------------
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux